Meet PS22 Chorus, the celebrated elementary school choir in Staten Island, N.Y.
The group is a YouTube sensation. The kids have performed with the likes of Katy Perry and Stevie Nicks of Fleetwood Mac, and had the honor of closing the Oscars with a breathtaking performance of "Over the Rainbow."
So they're somewhat of a big deal. But this could be their most powerful performance yet.
At the end of each year, the group performs a special song, led by director Gregg Breinberg. This year, they dedicated their special song to Adriana Lopez, a PS22 teacher who was recently diagnosed with breast cancer.